JP3100841B2 - Rotational position detecting device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational position detecting device for detecting a rotational position of a rotating machine using a resolver and a method therefor.

[0002]

2. Description of the Related Art A resolver is used for detecting a rotation angle and a speed because a resolver can easily detect a rotational position of an electric motor. Japanese Patent Application Laid-Open No. 59-54917 discloses the detection of a phase difference of a rotational position detecting device using a conventional resolver.

FIGS. 7 and 8 show the configuration of a conventional rotational position detecting device. The rotation position detecting device includes an excitation signal generation circuit 1 that outputs excitation voltages V _s1 and V _s2 that are electrically shifted by 90 ° from _{each other} .
A resolver 2 that outputs a sine wave V _r1 delayed in phase with respect to the excitation voltages V _s1 and V _s2 from the excitation signal generation circuit 1;
A phase circuit 3 for outputting a sine wave V _r2 delayed by 90 ° with respect to the sine wave V _r1 from the resolver 2, and excitation voltages V _s1 , V
It consists phase comparator circuit 4 for calculating the phase difference based on the _s2 and the sine wave V _r1, V _r2.

[0006] The excitation voltage V _s1 from the excitation signal generation circuit 1,
V _s2 excites the winding 5 on the stator side of the resolver 2 at sin ωt and the winding 6 on the stator side at cos ωt to generate a rotating magnetic field.

At this time, the winding 5 on the stator side of the resolver 2
When the rotational positional relationship between the motor and the rotor-side winding 7 differs by θ as shown in FIG.
An AC voltage having a phase relationship of (ωt−θ) is induced.

[0006] The induced AC voltage is input to the phase circuit 3 to output cos (ωt-θ) 90 ° out of phase. The sine wave sin (ωt−θ), cos
(Ωt−θ) and the excitation voltages V _s1 and V _s2 from the excitation signal generation circuit 1 and the phase comparison circuit 4 executes sin ωt · cos
(Ωt−θ) −cos ωt · sin (ωt−θ) is calculated to determine the phase difference.

[0007]

However, in a conventional rotation position detecting device using a resolver with two-phase excitation and one-phase output,
Since the rotor does not form a perfect circle due to the structure of the resolver, an error occurs due to the output of the resolver. Therefore, noting that many of these errors are 2n times as long as one period of the resolver, the present invention provides a rotational position detecting device and a method for simply detecting high rotational accuracy by canceling out these errors. The purpose is to do.

[0008]

According to a first aspect of the present invention, there is provided a rotational position detecting apparatus for generating excitation signal for outputting voltages which are electrically out of phase with each other by 90 °. A resolver that receives an output voltage from the excitation signal generating means and outputs a voltage delayed in phase corresponding to the output voltage from the excitation signal generating means, one output voltage from the excitation signal generating means and a signal from the resolver; First phase difference detection means for obtaining a phase difference from one output voltage; and second phase difference for obtaining a phase difference between the other output voltage from the excitation signal generation means and the other output voltage from the resolver. And a mean calculating means for calculating an average of a phase difference from the first phase difference detecting means and a phase difference from the second phase difference detecting means.

According to a second aspect of the present invention, there is provided an excitation signal generating means for outputting voltages which are electrically 90 ° out of phase with each other, and an output voltage from the excitation signal generating means is input to the excitation signal generating means. A resolver that outputs a voltage delayed in phase corresponding to an output voltage from the signal generating means, two output voltages from the exciting signal generating means and two output voltages from the resolver, and the exciting signal generating means And a second phase difference between the other output voltage from the excitation signal generating means and the other output voltage of the resolver, and a first phase difference between one output voltage of the resolver and one output voltage of the resolver. It is characterized by having phase difference detecting means to be obtained, and average value calculating means for obtaining an average of the first phase difference and the second phase difference from the phase difference detecting means.

According to a third aspect of the present invention, there is provided a rotational position detecting method, wherein voltages which are electrically shifted by 90 ° from each other are inputted to the resolver from the excitation signal generating means and the resolver converts the voltages to the output voltage from the excitation signal generating means. A corresponding phase-lagged voltage is output, and a first phase difference is obtained from one output voltage from the excitation signal generation means and one output voltage from the resolver, and the other is output from the excitation signal generation means. A second phase difference is obtained from the output voltage and the other output voltage from the resolver, and an average of the first phase difference and the second phase difference is obtained.

[0011]

According to a first aspect of the present invention, there is provided a rotational position detecting device, wherein voltages which are electrically shifted by 90 ° from each other are inputted to the resolver from the excitation signal generating means and the resolver responds to the output from the excitation signal generating means by the resolver. Output the delayed voltage
One output voltage from the excitation signal generation means and one output signal from the resolver are input to a first phase difference detection means to obtain a phase difference, and the other output voltage from the excitation signal generation means and the other The other output voltage of the resolver is input to the second phase difference detection means to obtain a phase difference, and the phase difference from the first phase difference detection means and the phase difference from the second phase difference detection means are calculated. The average of the phase difference is input to the average value calculation means.

According to a second aspect of the present invention, there is provided a rotational position detecting device.
A voltage that is electrically 90 ° out of phase from the excitation signal generation means is input to the resolver, and a voltage delayed in phase corresponding to the output from the excitation signal generation means is output from the resolver. And two output voltages from the resolver are input to a phase difference detecting means, and a first phase difference between one output voltage from the excitation signal generating means and one output signal from the resolver is obtained. And a second phase difference between the other output voltage from the excitation signal generating means and the other output voltage of the resolver is calculated, and the first phase difference and the second phase difference are averaged. The average of the phase difference is obtained by inputting to the means.

According to a third aspect of the present invention, there is provided a method for detecting a rotational position.
A voltage electrically shifted by 90 ° from each other is input to the resolver from the excitation signal generating means, and a voltage delayed in phase corresponding to the output voltage from the excitation signal generating means is output from the resolver. And a first phase difference is obtained from one output voltage from the resolver and one output voltage from the resolver, and a second phase difference is obtained from the other output voltage from the excitation signal generating means and the other output voltage from the resolver. A phase difference is obtained, and an average of the first phase difference and the second phase difference is obtained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a rotation position detection device according to the present embodiment.
An excitation signal generation circuit 11 that outputs excitation voltages V _s11 and V _s12 electrically 90 ° out of phase, and a sine wave V whose phase is delayed with respect to the excitation voltages V _s11 and V _s12 from the excitation signal generation circuit 11. _r11, a resolver 12 for 2-phase output for outputting the V _r12, the first phase difference detection circuit 13 for determining the phase difference between the sine wave V _r11 from excitation voltage V _s11 resolver 12 from the excitation signal generating circuit 11 A second phase difference between the excitation voltage _Vs12 from the excitation signal generation circuit 11 and the sine wave _Vr11 from the resolver 12 is _calculated .
And an average value calculation circuit 15 for calculating the average of the output of the first phase difference detection circuit 13 and the output of the second phase difference detection circuit.

Next, the operation will be described with reference to the flowchart of FIG. First, voltages having phases that are electrically shifted from each other by 90 ° are input to the resolver 12 from the excitation signal generation circuit 11 (step 1).

Next, the resolver 12 outputs a voltage delayed in phase corresponding to the output from the excitation signal generating circuit 11 (step 2). Then, the excitation signal generation circuit
One output voltage from the output signal 11 and one output signal from the resolver 12 are input to a first phase difference detection circuit 13 to obtain a phase difference, and the other output voltage from the excitation signal generation circuit 11 and the resolver The other output voltage of 12 is input to a second phase difference detection circuit 14 to obtain a phase difference (step 3).

As a result, the phase difference from the first phase difference detection circuit 13 and the phase difference from the second phase difference detection circuit 14 are input to an average value calculation circuit 15 to obtain the average of the phase difference. (Step 4).

The operation of the resolver 12 will be described with reference to FIG. The excitation voltages V _s11 and V _s12 from the excitation signal generation circuit 11
Excites the winding 16 on the stator side of the resolver 12 with sin ωt and the winding 17 on the stator side with cos ωt to generate a rotating magnetic field.

At this time, if the rotational position relationship between the stator-side winding and the rotor-side winding of the resolver 12 is different from each other by θ, sin (ωt−θ) is obtained from the rotor-side winding 16. An AC voltage having a phase relationship of cos (ωt−θ) is induced from the winding 17 on the rotor side.

The phase difference detecting circuit will be described with reference to FIG. The first phase difference detection circuit 13 includes an excitation signal generation circuit 11
A first square wave creating circuit 20 for creating a square wave from the excitation voltage V _s11 from the first circuit, a second square wave creating circuit 21 for creating a square wave from the sine wave V _r11 from the resolver 12, and a first square wave. It comprises a phase difference calculation circuit 22 for calculating a phase difference from the output of the wave generation circuit 20 and the output of the second square wave generation circuit 21.

The first square wave generation circuit 20 receives the excitation voltage V _s11 from the excitation signal generation circuit 11 as input, and _adds +1 when the excitation voltage is positive and −1 when the excitation voltage V _s11 is negative. Output. Therefore, the output of the first square wave generation circuit 20 is
It becomes a square wave whose phase is synchronized with the excitation voltage _Vs11 .

Similarly, the output of the second square wave generating circuit 21 is a square wave whose phase is synchronized with the sine wave _Vr11 from the resolver 12. The phase difference calculation circuit 22 outputs the phase difference θ as θ ₁ from the output of the first square wave generation circuit 20 and the output of the second square wave generation circuit 21.

[0023] In the same manner the second phase difference detection circuit 14 outputs a phase difference theta between sine wave V _r12 from excitation voltage V _s12 resolver 12 from the excitation signal generating circuit 11 as theta _2. As shown in FIG. 5, although the output theta ₁ of the first phase difference detection circuit 13 outputs theta ₂ of the second phase difference detection circuit 14 has a detection error caused by the resolver together, of the error the polarity is different, the average value calculating circuit 15 in the output theta ₁ of the first phase difference detection circuit 13 and the output theta ₂ of the second phase difference detection circuit 14
, The detection error can be canceled out.

Therefore, the detection error of the phase difference can be reduced, and the rotational position can be detected with high accuracy. In the embodiment described above, the excitation voltage is applied to the stator-side winding of the resolver, and the induced voltage is extracted from the rotor-side winding. However, the voltage is applied to the rotor-side winding. However, a similar effect can be obtained even if a signal is taken out from the winding on the rotor side. Further, even if the phase difference detection is performed by one phase difference detection circuit as shown in FIG. 6, the same rotation phase detection can be performed.

[0025]

As described above, the rotational position detecting device according to the first aspect of the present invention comprises: an exciting signal generating means for outputting voltages electrically shifted by 90 ° from each other; And a resolver that outputs a voltage delayed in phase corresponding to the output voltage from the excitation signal generating means, and one output voltage from the excitation signal generating means and one output voltage from the resolver. A first phase difference detecting means for calculating a phase difference between the first and second signals; a second phase difference detecting means for calculating a phase difference between the other output voltage from the excitation signal generating means and the other output voltage from the resolver; An average value calculating means for calculating an average of a phase difference from the first phase difference detecting means and a phase difference from the second phase difference detecting means, to perform rotational position detection with high detection accuracy; Can be.

According to a second aspect of the present invention, there is provided a rotational position detecting device for generating excitation signal for outputting voltages electrically shifted by 90 ° from each other, and receiving the output voltage from the excitation signal generating device for inputting the voltage. A resolver that outputs a voltage delayed in phase corresponding to an output voltage from the excitation signal generating means, and two output voltages from the excitation signal generating means and two output voltages from the resolver that are input to generate the excitation signal A first phase difference between one output voltage from the means and one output voltage of the resolver, and a second phase difference between the other output voltage from the excitation signal generating means and the other output voltage of the resolver. , And average value calculating means for calculating an average of the first phase difference and the second phase difference from the phase difference detecting means. What to do Can be.

According to a third aspect of the present invention, there is provided the rotational position detecting method, wherein voltages which are electrically shifted by 90 ° from each other are inputted to the resolver from the exciting signal generating means, and the output voltage from the exciting signal generating means is outputted from the resolver. And a first phase difference is obtained from one output voltage from the excitation signal generating means and one output voltage from the resolver, and the other is output from the excitation signal generating means. A second phase difference is obtained from the output voltage of the resolver and the other output voltage from the resolver, and an average of the first phase difference and the second phase difference is obtained. It can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a rotation position detection device of the present invention.

FIG. 2 is a flowchart of a rotational position detecting method according to the present invention.

FIG. 3 is a configuration diagram of a resolver of the present invention.

FIG. 4 is a configuration diagram of a phase difference detection circuit of the present invention.

FIG. 5 is an output diagram of the phase difference detection circuit of the present invention.

FIG. 6 is a configuration diagram of a rotational position detecting device according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional rotational position detection circuit.

FIG. 8 is a configuration diagram of a conventional resolver.

[Explanation of symbols]

 1,11 ... excitation signal generation circuit 2,12 ... resolver 13,14,23 ... phase difference detection circuit 15 ... average value calculation circuit 20,21 ... square wave generation circuit 22 ... phase difference calculation circuit

Claims (3)

(57) [Claims] 1. An excitation signal generating means for outputting voltages electrically shifted by 90 ° from each other, and a phase corresponding to an output voltage from the excitation signal generating means to which an output voltage from the excitation signal generating means is inputted. A resolver that outputs a delayed voltage, and a first method for calculating a phase difference between one output voltage from the excitation signal generating means and one output voltage from the resolver.
Phase difference detecting means, second phase difference detecting means for obtaining a phase difference between the other output voltage from the excitation signal generating means and the other output voltage from the resolver, and the first phase difference detecting means An average value calculating means for calculating an average of a phase difference from the second phase difference and a phase difference from the second phase difference detecting means. 2. An excitation signal generating means for outputting voltages electrically 90 ° out of phase with each other, and a phase corresponding to an output voltage from said excitation signal generating means, the output voltage being input from said excitation signal generating means being input. A resolver that outputs a delayed voltage, two output voltages from the excitation signal generation means and two output voltages from the resolver are input, and one output voltage from the excitation signal generation means and one of the resolvers Phase difference detecting means for obtaining a first phase difference from the output voltage of the resolver and a second phase difference between the other output voltage from the excitation signal generating means and the other output voltage of the resolver; An average value calculating means for obtaining an average of the first phase difference and the second phase difference from the means. 3. The method according to claim 2, wherein the excitation signal generating means electrically connects the two with each other.
° The phase-shifted voltage is input to the resolver, and the resolver outputs a voltage delayed in phase corresponding to the output voltage from the excitation signal generating means, and outputs one of the output voltage from the excitation signal generating means and the resolver. A first phase difference is obtained from one of the output voltages of the first and second outputs, and a second phase difference is obtained from the other output voltage from the excitation signal generating means and the other output voltage from the resolver. A rotation position detection method, wherein an average of a phase difference and the second phase difference is obtained.